Brake



8- M. w. McCONKEY BRAKE Filed Feb. 8. 1

INVENTOR "meme Au is, 1921.

UNITED STATES 1,639,142 PATENT ,oFFic-n.

moztreorr'nmr w. McGONXEY, or ,wrmvrn'rrn, rumors, essrono'n 'ro ennnzz enema E CHICAGO, ILLINOIS, A CORPORATIQN OF ILLIN'UIS.

' BRAKE.

Application filed February 8, 1926. Serial No; 88,708.

This invention relates to brakes, and illustrated as embodied in a well-known type of three-shoe internal expanding automobile brake. lVhile the invention is "not necessarily limited to this type of brake,'an important object is to increase the holding power of such a brake in reverse by introducing an increased servo 'or self-omen 'gizing action in reverse.

:hored end of the shoe which it applies, andif desired overlapping said anchored end.

"When einbodiedin the illustrated type of brake, this gives two servo shoes, one most effective when the car is moving forward and the other in reverse, but both acting on the anchoredshoe. The first of these servo such as theabove-described toggle,'whic h is shoes is illustrated as connected to the unanchored end of the anchored shoe by a pivot or the'like, While the other acts on means,

connected to the pivot;

-. other featuresvof the'jinvent'ion relate to a novel arrangement ofrelease springsfand a stop todetermine the positions of the parts when the brake is released, and to other novel combinations of parts and desirable particular constructions which will be apparent from the following description of the illustrative embodiment shown in the accompanying drawing, in which:

' i Fig. 1 1s avertical section through the brake, just inside the head of the drum,

showing the shoes in side elevation;

Fig. 2 is a section on the line 2-2 of Fig. 1, showing in inside elevation the overlapping ends of two of the shoes;

Fig. 3' is asection, on the line 33 of Fig. 1, through the overlapping ends shown in Fig.- 2; and p Fig. 4 is a section on the line Hot Fig. 1, showing the connection of the linkage to the shoe.

The illustrated brake includes a drum 10, at the open side of which is a supp'ort'such as a backing platelQ, and within which is the friction means of the brake. The illustrated friction means includes a friction device comprising primary and secondary shoes 1 4: and 16, connected by means such as a floatlug pivot 18 and anchored by pivoting the end of shoe 16 on an anchor 20 carried by the backing plate 12, together with-an.

auxiliary shoe 22.

Shoes 14 and 22 may be T-shaped in cros scction, while shoe 16 may be generally channel scction to provide spaced stifiening flanges 24 straddling, at the opposite ends of the shoe, the ends of shoes .4 and 22, Pivot 18 directly connects the left ends (Fig. 1) of flanges 2 L to the straddled end of shoe l l. Pivot or anchor 20, for the right-hand ends of flanges 24, passed through ,a relatively large opening 26 in the stiflfen ing web of shoe 22. Shoes 14; and 2.2 are preferably identical and interchangeable, and the opening 26 of 5110014: may be bridged by a pin 28 connected to one end of a spring 30 connected at its other end to the backing plate 12. The brake maybe applied by means such .as a double cam 84, which forces toward the drum, againstthe resistance of a return spring 86, shoes 22 and 14. "When the car is 39 moving forwarohat which timethe drum in Fig. 1 is turning counter-clockwise, shoe 1% turns with the drum when applied and acts as aservo shoe on connection 18 to force shoe 16 against the drum against the resistance of an auxiliary return spring 38. The free ends of shoes 1-1 and '22 are shown, confined laterally by a plate 40 carried by posts 42 passing "through openings 44111 the shoes and carried by the backing plate 12;

According to an important feature of the present invention, auxiliary shoe 22 or its equivalent also acts as a servo shoe, especially when drum 10 in Fig. 1 is turning clockwise, i. e. when the vehicle is moving backward. In thus acting as a servo shoe, I prefer that it act on the unanchored end of shoe 16, for example on pivot 18, by novel power-multiplying means illustrated as a toggle including links and 52 on which the servo shoe acts through a link When thus arranged, links 52 may be pivoted on pivot '18 on opposite sidesv of shoe 14 and'between the flanges 24c of shoe 16, While links-5O are mounted on a pivot,-

carried by the backing plate 12. Asv the toggle opens to the left in Fig. 1, it will be seen that the a xihary return spring 38 tends to break the toggle, whereas when shoe 22 turns clockwise with toe drum it thrusts link 54 in a direction tending to straighten the toggle and force the nn'anehored ends oi shoe 16 toward the drum, Link 5 is shown forked at its firi 'ht-hand end (Fig, 1), to j project between ang es 24- oi' shoe i6 and to straddle the end of shoe 22, to which shoe it is connected by a pivot pin 58. 1 in 58 pro jects through relatively iar e openings 60 1D. flanges 24, and has an en arged head. 62 slidably engaging the backing piste 12. k I" 'When the brake is released,the idle positionsoflink .54 and of the lower end of shoe 22 are determined by a suitable stop 6 shown as an adjustable eccentric carried by plate 12, which fits into the angle between the link and the shoe, and against which I they are held by a spring 66. Sprin 66 is connected at one end to the backing p ate 12 and at its other end to link 54, and is inclined at such an angle as to urge both link Stand shoe 22 into engagement with stop 64:. Stop 64 thus determines the position of link 54 lengthwise, spring 38 being made too light to act throughthe toggle to force shoe. 22 away from step 54. However, spring 38 does break the toggle to swing shoe 16 away from the'di'um, as far as permitted by the 'seating'of stop (it in the angle between link 54 and shoe 22. Thus stop 64 acts through V the toggle to determine the idle position of 'shoelti.

It will be seen that, in the illustrated ar rangement, both of the shoes 14 and 22 are servo shoes tending to apply shoe 16, shoe let being the more efiective of the two when the Vehicle is moving forward, and shoe 22 being) the more efiective when the vehicle is moving backward. It is not my intention, however, to limit the sec e of thetinvention to the particular brake il ustrated, or other: wise than by the terms of the appended claims.

I claim:

1. A brake comprising, in combination, a plurality of at least three shoes arranged end to end, and applying means connecting the same end of the intermediate shoe to the two shoes at its opposite ends.

2. Abrake comprising, in combination, a pair of pivotally connected shoes, and a third shoe connected to the pivotally connected ends of said pair of shoes.

3. A brake comprising, in combination, a

drum, a pair of shoes, an anchor for one of ing the unanchored end of the anchored shoe against the drum.

4. A brake comprising, in combination, a drum, a pair of shoes, an anchor for one of the shoes at thercnd adjacent the other shoe,

means acting on the opposite end of said other shoe to force .it-against the drum, and

drum.

and having a connection 18 between their ad acent ends, applying means acting on the w unconnected end of one of the shoes, and auxiliary applying means acting on the connection between the shoes.

6. A brake comprisin in combination, a

pair of shoes arranged end. to; end and com nected at their adjacent ends, applying means acting on the unconnected end of one of the shoes, and auxiliary applying means acting on the connected ends of the shoes.

7. A brake comprising, in combination,

three shoes arranged end to end, and applying means through which. both end shoes act on the same end of the center shoe.

8. A brake comprising, in combination, a drum, a shoe engageable with the clinic a toggle-fined, at one end and connected at its other end to force the shoe against the drum, and an auxiliary shoe acting on the knuckle of said toggie to force thefirst shoe against the drum.

A brake comprising, eomhination, a drum, a support, shoe engageabie with. the drum, a toggle pivoted at one end on the support for forcing said shoe the drum, and an auxiliary shoe acting on toggle to force the first shoe against the sing, in combination, a drum, a shes, a device for forcing; shoe against the drum, an auxiliary shoe ehgageabie with the same none of the drum as first shoe operating said device and auxiliary means for forcing the first shoe against the drum independently oi' said device.

11. A brake comprising, in combination, a drum, a shoe engageabie with the drum, a toggle for forcing said shoe against the drum, an auxiliary shoe engageahle with the drum, and a link connected at one end to the auxiliary shoe at the other end to the toggle.

12. A brake comprising, in comhination, a drain. a shoe anchored at one end and engageable with the drum, and an auxiliary shoe overlapping the anchored end of said first shoe and acting on its nnanchored end to force it against the drum.

A brake comprising, in combination, a

amiable with the drum, and pair of shoes arranged at opposite ends of the anchored against the drum.

15. A brake comprising, in combination, a

drum, a shoe anchored at one end and engageable with the drum, and a pair of shoes arranged at opposite ends ofthe anchored shoe and both of which are connected to the unanchored end of the anchored shoe to force it against the drum.

16. A brake comprising, in combination, a drum, 3. shoe anchored at one end and engageable with the drum, and a pair of shoes overlapping opposite ends of the anchored shoe and both of which act onthe unanohored end of the anchored-shoe to force it against the drum. 1

17. A brake comprising, in combination, a first shoe anchored at one end, a second shoe at the unanchored end of the first shoe, a connection between said shoes, a third shoe at the anchored end of the first shoe, and means through which the third shoe acts on said connection to apply the first shoe. 18. A brake comprising, in combination, a first shoe, a second shoe at one end 'of the first shoe, a connection between said shoes, athird shoe at the other end of the first shoe, and means through which the third shoe acts on said connection to apply the first shoe. I

19. A brake comprising, in combination,- a drum, a pair of shoes engageable with the drum, a device through which one of said shoes forces the other against the drum,

and an auxiliary shoe also acting on said device.

erated by the auxiliary shoe and acting on the pivot.

21. A brake comprising, in combination, a drum, a pair of shoes engageable with the drum, a pivot connectingthe shoes, an auxiliary shoe, and a linkage connecting the auxiliary shoe and said pivot.

22. A brake comprising, in combination,

a drum, a pair of shoes engageable with the drum and one of which is anchored at the 1 end adjacent the other, one of the shoes having spaced flanges straddling the end of the other, a pivot at the end of the unanchored shoe, a link having arms projecting between the two -shoes and straddling the inner shoe and straddled-by said spaced flanges, and

actuating means operated by said link to force the anchored shoe against the drum.

23. A brake comprising, in combination, a drum, a friction device anchored at one end and engageable with the drum and including connected shoes, an auxiliary servo shoe at the anchored end of the friction device, brake-applying means for forcing against the drum the auxiliary shoe and the -unanchored end of the friction device, and

auxiliary power-multiplying connections operated by the auxiliary shoe for forcing said friction device against the drum.

24. A brake comprising, in combination, a drum, a friction device anchored at one end and engageable with the drum, an auxiliary servoshoe at the anchored end of the friction device, brake-applying means for forcing against the drum the auxiliary shoe and the unanchored 'end' of the friction device, and auxiliary power-multiplying connections between the auxiliary shoe and a part of the friction device between its ends.

25. A brakezcorn rising, in combination, a drum, an anchore shoe, 9. brake-applying toggle acting on said shoe, a s ring tending to breakthe toggle to urge the shoe away from the drum, an auxiliary shoe acting on the toggle in a manner tending to straighten it to force the' anchored shoe against the drum, a stop arranged to determine the position of the auxiliary shoe when the brake is released and also arranged to determine the osition of the toggle and through the togg e of the anchored shoe when the brake is released, and meansyieldingly urging the auxiliary shoe toward an idle position determined at least in part by the stop.

In testimony whereof, ,I have hereunto signed my name.

MONTGOMERY W. MGCONKEY.

DISCLAIMER 1,639,14E2.ZV[0ntg0mery W. MeUonkey, Wilmette, Ill. BRAKE. Patent dated August 16, 1927. Disclaimer filed September 8, 1930, by the patentee and the assignee, Bendz'm Brake Company.

Hereby jointly and severally disclaim from the scope of claims 2, 5, 6, 10, 18, 19, 20, and 21 of said patent all brake structures except those comprising at least three brake shoes of which an intermediate or secondary shoe is anchored to a fixed part.

[Oyjieial Gazette September 30, 1930.] 

